diff --git a/src/commands.ts b/src/commands.ts
index 8cae75452..495cbd210 100644
--- a/src/commands.ts
+++ b/src/commands.ts
@@ -150,6 +150,7 @@ import sandboxToggle from './commands/sandbox-toggle/index.js'
 import chrome from './commands/chrome/index.js'
 import stickers from './commands/stickers/index.js'
 import advisor from './commands/advisor.js'
+import provider from './commands/provider.js'
 import { logError } from './utils/log.js'
 import { toError } from './utils/errors.js'
 import { logForDebugging } from './utils/debug.js'
@@ -258,6 +259,7 @@ export const INTERNAL_ONLY_COMMANDS = [
 const COMMANDS = memoize((): Command[] => [
   addDir,
   advisor,
+  provider,
   agents,
   branch,
   btw,
diff --git a/src/commands/provider.ts b/src/commands/provider.ts
new file mode 100644
index 000000000..78080b769
--- /dev/null
+++ b/src/commands/provider.ts
@@ -0,0 +1,111 @@
+import type { Command } from '../commands.js'
+import type { LocalCommandCall } from '../types/command.js'
+import { getAPIProvider } from '../utils/model/providers.js'
+import { updateSettingsForSource } from '../utils/settings/settings.js'
+import { getSettings_DEPRECATED } from '../utils/settings/settings.js'
+import { applyConfigEnvironmentVariables } from '../utils/managedEnv.js'
+
+function getEnvVarForProvider(provider: string): string {
+  switch (provider) {
+    case 'bedrock':
+      return 'CLAUDE_CODE_USE_BEDROCK'
+    case 'vertex':
+      return 'CLAUDE_CODE_USE_VERTEX'
+    case 'foundry':
+      return 'CLAUDE_CODE_USE_FOUNDRY'
+    default:
+      throw new Error(`Unknown provider: ${provider}`)
+  }
+}
+
+// Get merged env: process.env + settings.env (from userSettings)
+function getMergedEnv(): Record<string, string> {
+  const settings = getSettings_DEPRECATED()
+  const merged = { ...process.env }
+  if (settings?.env) {
+    Object.assign(merged, settings.env)
+  }
+  return merged
+}
+
+const call: LocalCommandCall = async (args, context) => {
+  const arg = args.trim().toLowerCase()
+
+  // No argument: show current provider
+  if (!arg) {
+    const current = getAPIProvider()
+    return { type: 'text', value: `Current API provider: ${current}` }
+  }
+
+  // unset - clear settings, fallback to env vars
+  if (arg === 'unset') {
+    updateSettingsForSource('userSettings', { modelType: undefined })
+    // Also clear all provider-specific env vars to prevent conflicts
+    delete process.env.CLAUDE_CODE_USE_BEDROCK
+    delete process.env.CLAUDE_CODE_USE_VERTEX
+    delete process.env.CLAUDE_CODE_USE_FOUNDRY
+    delete process.env.CLAUDE_CODE_USE_OPENAI
+    return { type: 'text', value: 'API provider cleared (will use environment variables).' }
+  }
+
+  // Validate provider
+  const validProviders = ['anthropic', 'openai', 'bedrock', 'vertex', 'foundry']
+  if (!validProviders.includes(arg)) {
+    return { type: 'text', value: `Invalid provider: ${arg}\nValid: ${validProviders.join(', ')}` }
+  }
+
+  // Check env vars when switching to openai (including settings.env)
+  if (arg === 'openai') {
+    const mergedEnv = getMergedEnv()
+    const hasKey = !!mergedEnv.OPENAI_API_KEY
+    const hasUrl = !!mergedEnv.OPENAI_BASE_URL
+    if (!hasKey || !hasUrl) {
+      updateSettingsForSource('userSettings', { modelType: 'openai' })
+      const missing = []
+      if (!hasKey) missing.push('OPENAI_API_KEY')
+      if (!hasUrl) missing.push('OPENAI_BASE_URL')
+      return {
+        type: 'text',
+        value: `Switched to OpenAI provider.\nWarning: Missing env vars: ${missing.join(', ')}\nConfigure them via /login or set manually.`,
+      }
+    }
+  }
+
+  // Handle different provider types
+  // - 'anthropic' and 'openai' are stored in settings.json (persistent)
+  // - 'bedrock', 'vertex', 'foundry' are env-only (do NOT touch settings.json)
+  if (arg === 'anthropic' || arg === 'openai') {
+    // Clear any cloud provider env vars to avoid conflicts
+    delete process.env.CLAUDE_CODE_USE_BEDROCK
+    delete process.env.CLAUDE_CODE_USE_VERTEX
+    delete process.env.CLAUDE_CODE_USE_FOUNDRY
+    // Update settings.json
+    updateSettingsForSource('userSettings', { modelType: arg })
+    // Ensure settings.env gets applied to process.env
+    applyConfigEnvironmentVariables()
+    return { type: 'text', value: `API provider set to ${arg}.` }
+  } else {
+    // Cloud providers: set env vars only, clear settings.modelType
+    delete process.env.CLAUDE_CODE_USE_OPENAI
+    delete process.env.OPENAI_API_KEY
+    delete process.env.OPENAI_BASE_URL
+    process.env[getEnvVarForProvider(arg)] = '1'
+    // Clear settings.json to 'anthropic' to avoid validation errors
+    updateSettingsForSource('userSettings', { modelType: 'anthropic' })
+    // Ensure settings.env gets applied to process.env (in case it contains provider-specific creds)
+    applyConfigEnvironmentVariables()
+    return { type: 'text', value: `API provider set to ${arg} (via environment variable).` }
+  }
+}
+
+const provider = {
+  type: 'local',
+  name: 'provider',
+  description: 'Switch API provider (anthropic/openai/bedrock/vertex/foundry)',
+  aliases: ['api'],
+  argumentHint: '[anthropic|openai|bedrock|vertex|foundry|unset]',
+  supportsNonInteractive: true,
+  load: () => Promise.resolve({ call }),
+} satisfies Command
+
+export default provider
diff --git a/src/utils/model/providers.ts b/src/utils/model/providers.ts
index a082cd298..bce43ba92 100644
--- a/src/utils/model/providers.ts
+++ b/src/utils/model/providers.ts
@@ -8,6 +8,9 @@ export function getAPIProvider(): APIProvider {
   // 1. Check settings.json modelType field (highest priority)
   const modelType = getInitialSettings().modelType
   if (modelType === 'openai') return 'openai'
+  if (modelType === 'bedrock') return 'bedrock'
+  if (modelType === 'vertex') return 'vertex'
+  if (modelType === 'foundry') return 'foundry'
 
   // 2. Check environment variables (backward compatibility)
   return isEnvTruthy(process.env.CLAUDE_CODE_USE_OPENAI)